Track instrument



(No Model.)

- T. B. DIXON.

TRACK- INSTRUMENT.

Patented Nov. 3, 1896.

AHHHHHHHHHH- .llllllllllllll ll I., I. :VIJU

UNITED STATES PATENT OEEIcE.

THOMAS BULLITT DIXON, OF HENDERSON, KENTUCKY.

TRACK INSTRUMENT.

SPECIFICATION forming part of Letters Patent Ne. 570,700, dated November3, 189e.

Application filed September 12, 1895. Serial No. 562.263. (N0 model.)

To all whom it may concern:

Beit known that LTHOMAS B ULLITT DIXON, a citizen of the United States,residing at Henderson, in the county of Henderson and State of Kentucky,have invented certain new and useful'Improvement-s in Track Instruments;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention relates generally to track instru ments for operatingsignals or other apparatus designed to be operated by and in accordancewith the movements of trains upon a railway-track, and particularly to atrack instrument designed for operating the circuits of electricalrailway signaling systems.

The circuits of railway signaling systems are usually operated either bytrack-circuits formed by dividing the track into electricallyinsulatedsections, through the rails of which electric currents may be passed insuch a manner that the wheels of a train on one of said sections willeither short-circuit or complete the circuit through the rails of saidsection, or else the circuits are operated by circuit breakers orclosers, termed track instruments, which usually are operated bytrack-levers or similar devices arranged to be depressed by the wheelsof the train passing over the track or by electric currents passingthrough short insulated sections of track and arranged to be completedor short-circuited by trains passing over said sections. The use ofinsulated sections of track has been attended with many disadvantagesbecause of the diftlculty in securin g proper insulation between thelines of the rails, which necessitates unusually expensive constructionof the railway-bed and unusual care in the maintenance thereof, becauseexpensive bonding of ment under the iniiuence of the shock or jar ofpassing trains, which shallnot be liable to excessive wear, requiringcontinual replacesnow, ice, water, or dust.

' By my invention I provide a track instrument which does not require tobe operated by electrically-insulated track-sections or by track-leversor other similar devices operated by wheels of the train passing overthe track, which is not subject to inj ury or derangement from shock orjar, which is not affected by snow, ice, water, or dust, and which maybe located at a point distant from the railwaytrack, if so desired, soas to protect it from injury and interference. The essential diierencebetween m y track instrument and former track instruments lies in thesubstitution for an electric circuit arranged to be completed track foroperating the track instrument of a magnetic circuit produced by amagnet having poles so arranged Vthat a portion of the magnetic circuitis shunted or diverted from track, and is caused to pass throughportions of the train, such as the car wheels and axles, which conductmagnetism, The shunting of a portion of the'magnetic circuit away fromeration of a signal-controlling device so constructed and arranged as tobe operated by variations in strength of the magnetic field. Theportions of a train through which the magnetic circuit is passed, suchas the car of iron or steel, materials Which conduct magnetism, may forthe purpose of this application be said to be composed of magneticmaterials, and maybe termed magnetic 7 portions of the train.

The use of the magnetic field or circuit inment, and which shall not beaifected by or short-circuited by wheels passing over the t its normaleld when a train passes over the this field weakens the field and causestheopwheels and axles, which are always composed l the rails has beenrequired in order to insure stead of the electric circuit has theativan-4.95.,

l the electrical continuity of the rails, and betage that there is noleakage due to ,moistureMM 4 5 cause of the difficulty of insulatingonev secor tovgimpertect g,insnlationof.therails,the

tion of track electrically from another sectionoaflymagieticinsulationreguireglnbeipglafthe rail-joint at the point where theinsulating material is placed being, as a rule, undesirably weak. Theuse of track instruments has been objectionable because of thedifliculty of so constructing a track instrument that it' shall not beliable to breakage or to derangevaiationotthe Iiiageti'iield-is notdependent upon the making of a perfect contact between the wheels andthe rails, but may be effected even though the wheels do not actuallyinake contact with the rails, as where the rails are covered by sleet orby dust and sand; that the moving parts of the track instrument may belocated at a distance from the track and may be protected against thetransmission to them of shock or jar, and that where it is necessary toplace the track instrument in a magnetically-insulated tracksection, aswhere two track instruments must be placed in close proximity to eachother, the insulating material may be some strong non-magnetic metal,such as brass, so that the rail-joint at the point of insulation is notweakened.

My invention consists in the novel means employed for causing theoperation of a magnetically-operated signal-controlling device by trainspassing over the track; in the novel magnetically-operatedsignal-controlling device employed; in the connection of the cores ofthe magnet to the track-rails, thereby constituting the track-railspoles of the magnet and causing the magnetic circuit of the magnet topass through the wheels and axles of trains passing over the track, andin the novel combination,construction,and arrangement of the parts ofthe track instrument.

The objects of my invention are, irst, to provide a track instrumentwhich shall not require to be operated by electrical trackcircuits or byrail-levers or similar devices; second, to provide a track instrumentwhich shall not be affected by water, snow, ice, or dust, and which maybe so constructed that it shall not be affected by shock Vor jar due topassing trains, and, third, to make the track instrument simple inconstruction, as inexpensive as possible, durable, not liable toderangement, and easy of installation. These objects are attained in thetrack instrument. herein described and illustrated in the drawings whichaccompany and form a part of this application, in which the samereference-numerals indicate the same or corresponding parts, and inwhich- Figure 1 shows one form. of my track in strnment in place upon atrack, the rails being sectioned transversely. Fig. 2 is a similar viewshowing another form of my track instrument in which the contact-leveris placed to one side of and at some distance vfrom the rails, beingconnected therewith by! iiexible magnetic conductors, so that thetransmission of vibration from the rails to the contactelever may bereduced to a minimum; and Fig. 3 is a similar View illustrating anotherform of magnetic track instru* ment operating upon a somewhat differentprinciple from the track instruments shown in Figs. 1 and 2, but themagnet of which is likewise connected to the rails, this arrangement ofthe magnet being, as already statedy one feature of my invention.

In the drawings,1 and 2 are the track-rails, which may be supported uponties of wood or other non-magnetic material in the ordinary and commonway. Beneath the rails are electromagnets having cords 3 and i connectedto the rails and helices 5 and G surrounding the cores. A bar 7 ofmagnetic material connects the two cores 3 and 4, thus formingsubstantially an ordinary horseshoe electromagnet. A battery S isconnected by conductors 9 and 10 with the helices of the magnets andserves to energize the same.

Leading from the rails, or from the cores 3 and at in close proximity tothe rails, are magnetic conductors 11 and 12 in Fig. 1 and 11 and 12 inFig. 2, which in the track instrument shown in Fig. 2 may be iron barsand in the track instrument shown in Fig. 2 are iiexible magneticconductors, which may be composed of a number of strands of soft-ironwire formed into a cable. rllhese conductors extend toward each other,but do not quite meet, the gap between their poles being bridged by apivoted lever 13, of magnetic energized by passing current through theirhelices, they energize rails 1` and 2 andthe conductors 11 and 12. Asthe helices 5 and 6 are wound to energize their cores oppositely, rails1 and 2 are of opposite polarity, as are conductors 11 and 12.'Therefore contactlever 13, which is attached to and thereforemagnetized by, one ofthe conductors 12 or 12', is attracted stronglytoward the pole of the other conductor 11 or 11. Vhen, however,car-wheels are on the rails 1 and 2, as indicated in dotted lines,magnetic circuit is diverted or shunted to a great extent at least fromthe magnetic field between the conductors 11 and 12 or 11 and 12',and iscaused to pass through the rails and car wheels and axles, thus greatlyreducing the strength of tractile spring 14 may draw the contact-lever13 away from the pole of conductor 11, causing it to break contact withfront stop 15 and to make contact with back stop 16. The lever 13 may beconnected with one terminal of an electric circuit controlling a signalor other device which it is desired to have operated by the trackinstrument, and either stop 15 or 16, or both, may be contactpoints,terminals of electric' circuits, so that the ICO Ilo`

Vthe iield of these conduct-ors, so that the retrack instrument isadapted for operating both normally open circuits and normallyclosedcircuits. It may also be used to operate the controlling-valve of apneumatic or hydraulic signal system or other signal-con trolling'device.

As soon as the wheels have passed over the rails 1 and 2 the magneticcircuit is restored in full strength to the field between conductors 11and 12 and the lever 13 is reattracted. As the car-wheels commonly usedare frequently made of hard iron and are of small magnetic permeability,and as it is important,

in order to insure prompt movement of the lever 13, that the variationsin the strength of the ield of magnetic conductors 11 and 12, caused bywheels passing over the track, shall be very considerable, it may benecessary to use conductors 11 and 12 of considerable magneticresistance. This may be accomplished by making the conductors of smallsize, or, if that be not desirable or sufficient, by breaking theircontinuity at one or more points by interposing sections of non-magneticmaterial. Itis not necessary, however, that the magnetic resistance ofconductors 11 and 12 shall actually be greater than that of the carwheels and axles, what is necessary being simply such a relation betweenthe magnetic resistance of conductors 11 and 12 and of the car wheelsand axles that the presence of lcar-wheels on the rails shall cause theshunting o f enough of the magnetic eld through the wheels and away fromconductors 11 and 12 to perceptibly weaken their magneticV strength andto permit the spring 14 to draw the lever 13 away from the pole ofconductor 11. Y

In the track instrument shown in Fig. l the lever 13 and the conductors11 and 12 are placed between the rails. In order to reduce danger offalse operation of the lever 13, due to the shock or jar of passingtrains, the lever 13 may be arranged to swing in a horizontal planeinstead of in a vertical plane, there being less vibration in ahorizontal plane than in a vertical plane. Conductors 11 and 12 may,however, be led off to one side of the track, as are the conductors 11'and 12' shown in Fig. 2. To further reduce the ,danger of falseoperation of lever 13, owing to shock or jar, the poles of conductors11' and 12 and the lever 13 may be supported upon some solid support, asa pile driven deep into the earth, and flexible magnetic conductors 11'and 12', composed, as above stated, of a number of small soft-ironWires, may be used, which, because of their flexibility, will nottransmit vibration to the lever 13 to any appreciable extent.

than the air is provided, thus causing a very considerable variation inthe strength of the magnetic field, which induces a current in thesecondary coils of the helices 5 and 6', thus deiiecting the armature ofrelay 19. Vhenl lects the'armature of relay 19 back toits normalposition.

Relay 19, together with conductors 17 and 18 and the secondary coils ofhelices 5' and 6', may be considered a magnetically-operatedsignal-controlling device, since it is operated by the currents inducedin these helices and conductors by variation in the field of the magnet.

A safety-relay l2O may be placed in the circuit of battery 8, as shownin Fig. 3, which, in case of variation of the magnetic field of magnets5' and 6', due to the failure of battery 8 or to breakage of itscircuit, will break a signal-circuit or otherwise operate a signal,indicating that the track instrument is out of order, and will preventthe signals of the block from going to safety In allV of the forms oftrack instrument herein described, whether the lever 13 operates everytime a pair of wheels 'passesover' the track instrument orwhethe'rthejlever operates only once while thewhole train is passing jdepends'Vupon the strength of the magnets used and upon the length of themagnetically continuous rail-sections used. A If the rails bemagnetically continuous for a distance considerably greater than the-distance between two adjacent pairs of wheels of a car, and ii' themagnetsv be suihciently powerful to energize the Whole length of therail-section, then lever 13 will operate once only While the train ispassing; but'if the railsection to which'the magnets 5 and 6 areconnected be magnetically continuous for a distance shorter than thedistance between two adjacent pairs of Wheels of a car, then the lever13 will be operated each time a pair of wheels passes over the trackinstrument.

The connection of the cores of the magnet with the track-rails'sol as toconstitute the rail-poles of the magnet is an important feature of myinvention, for not only is it possible by varying the length of therail-sections to which the magnets are connected to cause the trackinstrument to operate each time a pair of wheels pass over the trackinstrument, or once only during the passage of a train, at will, but thetrack-rails form very eicient poles for causing the magnetic cir-` cuitto pass through the car Wheels and'axles. The passing of the magneticcircuit through the car wheels and axles, rather than through specialarmatures carried upon the train, is important, since it avoids thenecessity of specially equipping cars with special armaL tures foroperatingr the track instrument.

Permanent magnets maybe used instead of electromagnets, and I do notlimit myself to the use of electromagnets.

Having thus completely described my in- IOO vent-ion, what I claim, anddesire to secure by Letters Patent, isv l. In a track instrument, thecombination, with a magnet producing a magnetic field adapted toinfiuence a magnetically-operated signalcontrolling device, said magnethaving pole-pieces so arranged that when a train passes over the track aportion of the magnetic circuit is diverted from said field by beingshunted through magnetic portions of the train, and the magnetic fieldis thereby Weak ened, of an armature movably mounted in said magneticfield and arranged to be influenced thereby, a retractile deviceopposing the action of said magnetic field on said armature, wherebywhensaid magnetic field is weakened said armature is retracted, and asignal-controlling device operated by the :movement of the armature,substantially as described.

2. In a track instrument, the combination, with a magnet producing amagnetic field adapted to influence a magnetically-operatedsignal-controlling device, said magnet having pole-pieces so arrangedthat when a train passes over the track a portion of the magneticcircuit is diverted from said field by being shunted through magneticportions of the train, and the magnetic field is thereby weakened, of alever of magnetic material, movably mounted and arranged to beinfluenced by the said field ofsaid magnet, a retractile device opposingthe action of said magnetic field on said lever, whereby when saidmagnetic field is weakened said lever is retracted, and asignal-controlling device operated by the movement of the lever,substantially as described.

3. In a track instrument, the combination, with a magnet havingpole-pieces arranged to produce a magnetic field in the line of? motionof a train passing over the track, whereby when a train passes over thetrack the magnetic field is caused to pass through magnetic portions ofthe train and a path for the magnetic field of less resistance than thenormal path is thereby provided, of a second set of pole-pieces for saidmagnet producing a magnetic field, and a lever of magnetic material,movably mounted in said magnetic field, and having a retractile deviceopposing the action of the magnetic field thereon, and arranged to drawthe lever away from its normal position when the strength of the fieldof said lastnamed pole-pieces is diminished, substantially asdescribed.A

i. In a track instrument, the combination, with a magnet havingpole-pieces arranged to produce a magnetic field in the line of motionof a train passing over the track, whereby when a train passes over thetrack the magnetic field is caused to pass through magnetic portions ofthe train and a path for the magnetic field of less resistance than thenormal path is thereby provided, of a second set of pole-pieces for saidmagnet and a lever of magnetic material, connected to one of saidlast-named pole-pieces and arranged to be attracted to the other, but toswing away there'- from when the strength of the field of saidlast-named pole-pieces is diminished, substantially as described.

5. In a track instrument, the combination,

with a magnet having its poles connected with the track-rails, of'magnetic conductors connected with said magnet-poles, a lever. ofmagnetic material connected'with one of said conductors and arranged tobe attracted by the l other conductor, and a retractile device fordrawing said lever away from said second conductor, whereby, when themagnetic circuit through said conductors is short-circuited by wheelspassing over the track, said lever is operated, substantially asdescribed.

6. In a track instrument, the combination, with a magnet having itspoles connected with the track-rails, of flexible magnetic conductorsconnected with said magnet--poles, a lever of magnetic materialconnected with one of said conductors and arranged to be attracted bythe other conductor, and a retractile device for drawing said lever awayfrom said second conductor, whereby, when the magnetic circuit throughsaid conductors is short-circuited by wheels passing over the track,said lever is operated, substantially as described,

7. In a track instrument, the combination, with a magnet having itspoles connected with the track-rails, of magnetic conductors connectedwith said magnet-poles, a lever of magnetic material connected with oneof said conductors and arranged to be attracted by Athe other conductor,a retractile device for drawing said lever away from said secondconductor, whereby, when the magnetic circuit through said conductors isshort-circuited by wheels passing over the track, said lever isoperated, and signal-controlling devices operated by said lever,substantially as described.

S. In a track instrument, the combination,

with a track-magnet, having its cores con-` nected to oppositetraek-rails, thereby constituting the rails poles of the magnet andproducing a magnetic field extending across the track which will passthrough the wheels and axles of a train passing over the track,

of a signal-controlling device operated by the passage of said magneticfield through the wheels and axles, substantially as described.

In testimony whereof I aitx my signature in presence of two witnesses.

THOMAS BULLITT DIXON.

\Vitnesses:

CAROLINE E. DAvmsoN, HARRY M. MARBLE.

IlO

IIS

